Recent years have seen an evolution toward higher-power microprocessor chips. This evolution in turn has driven interest in high-performance cooling systems (e.g., heat sinks) to evacuate heat from the chips, because the more powerful chips tend to generate more heat in operation. If this heat is not adequately dissipated, the chips are likely to fail.
Two common systems for evacuating heat from microprocessor chips use either air or fluid as a transport means to remove heat from a chip. While both systems perform well, they are both also subject to several drawbacks. For instance, air-based cooling systems tend to be rather large and noisy, and chips having high power densities (e.g., in excess of 100 W/cm2) are difficult to cool using an air-based system. Fluid cooling systems, while typically smaller, quieter and more efficient than air-based systems, are also more complex and more costly to implement and maintain. Moreover, the risk of leaks has impeded the general acceptance of fluid-based systems.
Air cooling is the default cooling method in most low end and midrange computer and server systems. Air cooling is typically favored by manufacturers because it operates in all environments and allows flexible installation and handling of servers without the complexity of plumbing. In data centers that employ many servers, however, the air cooling systems tend to experience especially large heat loads. Thus, in the data center environment, it is advantageous to have the option to additionally provide fluid cooling, which is not only a more efficient cooling method, but also costs less in terms of power and infrastructure.
Thus, there is a need for a cooling system that selectively allows heat to be dissipated from a heat generating device via air, fluid or both.